That's very possible, I think the problem is I'm confused by their use of the word "myth".
When I hear full-time employment and men, I'm not aware of any myth that men are continously employed I think the of the societal standard that men must be continously employed. Rereading the paper, it still seems like they're sorting conflating things because they explicitly compare the men's employment to the fact that women "opt-out" of the workforce.
So to be clear, I'm not questioning the merit/validtiy of the study, but the way they've phrased their finding is odd (at the very least).